In recent years, there has been an increasing use of compact, pocket-size electronic personal organizers that store personal scheduling information such as appointments, tasks, phone numbers, flight schedules, alarms, birthdays, and anniversaries. Some of the more common electronic organizers are akin to hand-held calculators. They have a full input keyboard with both numeric keys and alphabet keys, as well as special function keys. The organizers also have a liquid crystal display (LCD) which often displays full sentences and rudimentary graphics.
Apart from personal organizers, it is common for many people to maintain appointment calendars and task lists on their desk-top personal computers. One example time management software is Microsoft's.RTM. Schedule+.TM. for Windows.TM. which maintains daily appointment schedules, to-do lists, personal notes, and calendar planning. This information is often a duplicate of that maintained on the portable personal organizer.
People who electronically maintain their schedules often enter the same information two different times: once into their personal computer and once into their portable personal organizer. This repetitive effort is inconvenient and affords more opportunity for error. Additionally, there is a risk of incorrectly entering conflicting schedules. For example, the personal computer might show a meeting with a client at 8:00 am, while the portable personal organizer might indicate that the same meeting is at 3:00 pm. To avoid this situation, careful planners are required to meticulously enter the data into both the computer and personal organizer and then double-check each entry to ensure the accuracy of the dual scheduling system.
Accordingly, it would be nice if a person only had to enter his/her schedule once, say into the computer, and then have the data automatically downloaded to the personal organizer. One approach to accomplishing automatic data transfer is to interconnect the computer and personal organizer using a physical cord or conductor. For instance, a serial RS232 cable can be used to connect the serial port of the computer with a specially configured I/O port on the personal organizer. In this manner, data entered into the computer can be electronically transferred to the personal organizer over the serial cable. While this system reduces the opportunity for entry error, it is inconvenient because the user must either carry a cable along with the personal organizer or leave the cable with a specific computer and only load information from that computer. Accordingly, it is desirable to provide a wireless communication system that is not reliant on a cable interface.
One wireless technique for automatically loading data into a personal organizer involves technology introduced by Timex Corporation of Middlebury, Conn., which facilitates data transfer from a personal computer to an electronic watch. In recent years, electronic watches have evolved to the point that they can function as personal organizers. Like the pocket-size devices described above, such watches can be programmed with certain key appointments, tasks, phone numbers, flight schedules, alarms, birthdays, and anniversaries. In comparison to pocket-size personal organizers, however, it is difficult to enter data into a watch. This difficulty is due in large part to the limited number of input buttons and display characters available on reasonably-sized watches. Most watches are limited to having only three or four input buttons. A wearer programs a watch by depressing one or more buttons several times to cycle through various menu options. Once an option is selected, the user depresses another button or buttons to input the desired information. These input techniques are inconvenient and difficult to remember. Such techniques are particularly inconvenient when a wearer wishes to enter an entire month's schedule. Although watches have been made with larger numbers of input keys, such watches are usually much too large for comfort, and tend to be particularly unattractive.
To overcome the inconvenience of entering data to a watch, Timex devised its Data-Link.TM. watch which can be programmed using optical data transmission. The face of the watch has an optical sensor which is connected to a digital serial receiver, better known as a UART (universal asynchronous receiver/transmitter). The watch expects to receive a serial bit transmission in the form of light pulses at a fixed bit rate. A pulse represents a binary `0` bit, and the absence of a pulse represents a binary `1` bit. In the Data-Link.TM. system, the CRT (cathode ray tube) or other scanned-pixel display of a personal computer is used to provide light pulses to the watch. Although it appears to a human viewer that all pixels of a CRT are illuminated simultaneously, the pixels are actually illuminated individually, one at a time, by an electron beam which sequentially scans each row of pixels beginning with the top row and ending with the bottom row. It is this characteristic of a CRT and of other scanned display devices which is utilized to transmit serial data to the Data-Link.TM. watch.
While the CRT-based method has proven effective, it employs rather complicated transmission and timing schemes to ensure that the lines displayed on the CRT are interpreted as pulses by the watch's UART. For example, the watch is set to receive data at a fixed rate of, say, approximately 2K baud. However, the pace at which an electron beam scans horizontal lines depends on the frequency of the CRT, which varies among CRTs. Accordingly, the watches are either preset to operate with one particular type of CRT, or additional control is needed to enable the watch to communicate with different types of CRTs.
Another drawback of the Data-Link.TM. system is that it is limited to CRTs. LCD-based monitors such as those found in laptops do not emit enough light to be sensed by the watch.
Accordingly, there remains a need for a system for downloading data from a computer to an electronic personal organizer which is convenient, capable of wide use, and does not involve sophisticated procedures to initiate or conduct the data transfer task. It is an object of this invention to provide such as system.